These are some of the bewildering range of apparently innocuous household objects – and animals – that may be killing us indoors, according to a new report from the Royal College of Physicians and the Royal College of Paediatrics and Child Heath.

Most of us spend most of our lives indoors. So, how can we improve the air we breathe?

We should live more like our grandmothers and throw open the windows of our homes for a few minutes every day, says Professor Stephen Holgate, an asthma expert at the University of Southampton who led the report. Modern, energy-efficient homes may be less leaky, but that means it is vital to introduce fresh air to dilute chemical pollution and remove moisture, which encourages moulds. Of course, if the air isn’t fresh – if you live on a polluted main road, for instance – this may not be such a good solution.

Holgate believes there has been little scientific investigation of indoor air pollution in Britain because it is an unseen problem (unlike 1950s smog). He says there is a reluctance to “interfere with industry”, too.

Until there is more evidence, should we use fewer domestic chemicals? “Yes, we should. It has gone too far,” says Holgate. “There are 15,000 chemicals circulating in an average human. Many are in tiny quantities, but we need to find out more about how these mixtures interact when they get inside the human body – especially the foetus, which is very sensitive.”

Although pollen-producing cut flowers are mentioned as a potential problem in the report, pot plants may mitigate some indoor pollution. Chemicals in air fresheners and scented household products produce formaldehyde when they react with the air. Everyday exposure can irritate the lungs and may contribute to asthma, cancers and other illnesses. A recent test for the BBC’s Trust Me, I’m a Doctor suggested that house plants such as the humble spider plant can reduce levels of formaldehyde. (Formaldehyde is also emitted by furniture; the US has set legal limits for formaldehyde emissions from wood products such as MDF at 0.09 parts a million.)

“We can’t introduce laws to control what people do in their houses, but we can make people aware,” says Holgate. He hopes that more people will buy portable air-pollution monitors, which work with apps to measure air quality – a bit like personal fitness-monitors. Once we can measure bad air, we can avoid it. “That’s real people power,” says Holgate. “That’s going to change things.”